:: [[a]] -> [[a]] package:universe-base

Like diagonal, but expose a tiny bit more (non-semantic) information: if you lay out the input list in two dimensions, each list in the result will be one of the diagonals of the input. In particular, each element of the output will be a list whose elements are each from a distinct input list.

Slightly unfair n-way Cartesian product: given a finite number of (possibly infinite) lists, produce a single list such that whenever vi has finite index in list i for each i, [v1, ..., vn] has finite index in the output list.

Very unfair n-way Cartesian product: same guarantee as the slightly unfair one, but not as good in the same sense that the very unfair 2-way product is worse than the slightly unfair 2-way product.